ISOSORBIDE DINITRATE is a type of vasodilator. It relaxes blood vessels, increasing the blood and oxygen supply to your heart. This medicine is used to prevent and to treat chest pain caused by angina. This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care providers before I take this medicine?

They need to know if you have any of these conditions:

• low blood pressure
• previous heart attack or heart failure
• anemia
• an unusual or allergic reaction to isosorbide dinitrate, nitrates, other medicines, foods, dyes, or preservatives
• bleeding in the brain or recent head trauma
• overactive thyroid
• pregnant or trying to get pregnant

How should I use this medicine?

Place this medicine under the tongue. Follow the directions on the prescription label. Do not cut, crush or chew this medicine. Take this medicine 15 minutes before an activity that may cause chest pain or as directed. Do not take your medicine more often than directed.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following:

• medicines used to treat erectile dysfunction (ED) like sildenafil, tadalafil, and vardenafil

This medicine may also interact with the following:

• alcohol
• medicines for high blood pressure
• ethanol or phosphodiesterase type 5 inhibitors
• other medicines for angina or heart failure

This list may not describe all possible interactions. Give your health care providers a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What side effects may I notice from this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:

• bluish discoloration of lips, fingernails or palms of hands
• irregular heartbeat, palpitations
• frequent, continuing, or severe chest pain
• low blood pressure
• nausea, vomiting
• persistent headache
• rapid or slow heartbeat
• unusually weak or tired

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

• flushing of the face or neck
• rash
• dizziness
• headache
• lightheadedness

This list may not describe all possible side effects.

What should I watch for while using this medicine?

Check your heart rate and blood pressure regularly while you are taking this medicine. Ask your doctor or health care professional what your heart rate and blood pressure should be and when you should contact him or her. Tell your doctor if you feel your medicine is no longer working.

You may get dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. To reduce the risk of dizzy or fainting spells, do not sit or stand up quickly, especially if you are an older patient. Alcohol can make you more dizzy, and increase flushing and rapid heartbeats. Avoid alcoholic drinks.

Do not treat yourself for coughs, colds, or pain while you are taking this medicine without asking your doctor or health care professional for advice. Some ingredients may increase your blood pressure.

Where should I keep this medicine?

Keep out of the reach of children.

Store at room temperature, approximately 25 degrees C (77 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.